This invention is directed to indazole compounds that mediate and/or inhibit cell proliferation, for example, through the inhibition of the activity of protein kinases, such as VEGF, CHK-1, and cyclin-dependent kinases (CDKs), such as CDK1, CDK2, CDK4, and CDK6. The invention is further related to pharmaceutical compositions containing such compounds and compositions, and to methods of treating cancer as well as other disease states associated with unwanted angiogenesis and/or cellular proliferation, by administering effective amounts of such compounds.
Uncontrolled cell proliferation is the insignia of cancer. Cell proliferation in response to various stimuli is manifested by a deregulation of the cell division cycle, the process by which cells multiply and divide. Tumor cells typically have damage to the genes that directly or indirectly regulate progression through the cell division cycle.
Hyperproliferative disease states, including cancer, are characterized by cells rampantly winding through the cell cycle with uncontrolled vigor due to, for example, damage to the genes that directly or indirectly regulate progression through the cycle. Thus, agents that modulate the cell cycle, and thus hyperproliferation, could be used to treat various disease states associated with uncontrolled or unwanted cell proliferation. In addition to cancer chemotherapeutic agents, cell cycle inhibitors are also proposed as antiparasitics (See, Gray et al., Curr. Med. Chem. 6, 859-875 (1999)) and recently demonstrated as potential antivirals (See, Schang et al., J. Virol. 74, 2107-2120 (2000)). Moreover, the applicability of antiproliferative agents may be expanded to treating cardiovascular maladies such as artherosclerosis or restenosis (See Braun-Dullaeus et al., Circulation, 98, 82-89 (1998)), and states of inflammation, such as arthritis (See, Taniguchi et al., Nature Med., 5, 760-767(1999)) or psoriasis.
Mechanisms of cell proliferation are under active investigation at cellular and molecular levels. At the cellular level, de-regulation of signaling pathways, loss of cell cycle controls, unbridled angiogenesis or stimulation of inflammatory pathways are under scrutiny, while at the molecular level, these processes are modulated by various proteins, among which protein kinases are prominent suspects. Overall abatement of proliferation may also result from programmed cell death, or apoptosis, which is also regulated via multiple pathways, some involving proteolytic enzyme proteins.
Among the candidate regulatory proteins, protein kinases are a family of enzymes that catalyze phosphorylation of the hydroxyl group of specific tyrosine, serine, or threonine residues in proteins. Typically, such phosphorylation dramatically perturbs the function of the protein, and thus protein kinases are pivotal in the regulation of a wide variety of cellular processes, including metabolisim, cell proliferation, cell differentiation, and cell survival. Of the many different cellular functions in which the activity of protein kinases is known to be required, some processes represent attractive targets for therapeutic intervention for certain disease states. Two examples are cell-cycle control and angiogenesis, in which protein kinases play a pivotal role; these processes are essential for the growth of solid tumors as well as for other diseases.
CDKs constitute a class of enzymes that play critical roles in regulating the transitions between different phases of the cell cycle, such as the progression from a quiescent stage in G1 (the gap between mitosis and the onset of DNA replication for a new round of cell division) to S (the period of active DNA synthesis), or the progression from G2 to M phase, in which active mitosis and cell-division occur. See, e.g., the articles compiled in Science, vol. 274 (1996), pp. 1643-1677; and Ann. Rev. Cell Dev. Biol., vol. 13 (1997), pp. 261-291. CDK complexes are formed through association of a regulatory cyclin subunit (e.g., cyclin A, B1, B2, D1, D2, D3, and E) and a catalytic kinase subunit (e.g., cdc2 (CDK1), CDK2, CDK4, CDK5, and CDK6). As the name implies, the GDKs display an absolute dependence on the cyclin subunit in order to phosphorylate their target substrates, and different kinase/cyclin pairs function to regulate progression through specific portions of the cell cycle.
The D cyclins are sensitive to extracellular growth signals and become activated in response to mitogens during the G1 phase of the cell cycle. CDK4/cyclin D plays an important role in cell cycle progression by phosphorylating, and thereby inactivating, the retinoblastoma protein (Rb). Hypophosphorylated Rb binds to a family of transcriptional regulators, but upon hyperphosphorylation of Rb by CDK4/cyclin D, these transcription factors are released to activate genes whose products are responsible for S phase progression. Rb phosphorylation and inactivation by CDK4/cyclin D permit passage of the cell beyond the restriction point of the G1 phase, whereupon sensitivity to extracellular growth or inhibitory signals is lost and the cell is committed to cell division. During late G1, Rb is also phosphorylated and inactivated by CDK2/cyclin E, and recent evidence indicates that CDK2/cyclin E can also regulate progression into S phase through a parallel pathway that is independent of Rb phosphorylation (see Lukas et al., xe2x80x9cCyclin E-induced S Phase Without Activation of the pRb/E2F Pathway,xe2x80x9d Genes and Dev., vol. 11 (1997), pp. 1479-1492).
The progression from G1 to S phase, accomplished by the action of CDK4/cyclin D and CDK2/cyclin E, is subject to a variety of growth regulatory mechanisms, both negative and positive. Growth stimuli, such as mitogens, cause increased synthesis of cyclin D1 and thus increased functional CDK4. By contrast, cell growth can be xe2x80x9creined in,xe2x80x9d in response to DNA damage or negative growth stimuli, by the induction of endogenous inhibitory proteins. These naturally occurring protein inhibitors include p21WAF1/CIP1, p27KIP1, and the p16INK4 family, the latter of which inhibit CDK4 exclusively (see Harper, xe2x80x9cCyclin Dependent Kinase Inhibitors,xe2x80x9d Cancer Surv., vol. 29 (1997), pp. 91-107). Aberrations in this control system, particularly those that affect the function of CDK4 and CDK2, are implicated in the advancement of cells to the highly proliferative state characteristic of malignancies, such as familial melanomas, esophageal carcinomas, and pancreatic cancers (see, e.g., Hall and Peters, xe2x80x9cGenetic Alterations of Cyclins, Cyclin-Dependent Kinases, and CDK Inhibitors in Human Cancer,xe2x80x9d Adv. Cancer Res., vol. 68 (1996), pp.67-108; and Kamb et al., xe2x80x9cA Cell Cycle Regulator Potentially Involved in Genesis of Many Tumor Types,xe2x80x9d Science, vol. 264 (1994), pp. 436-440). Over-expression of cyclin D1 is linked to esophageal, breast, and squamous cell carcinomas (see, e.g., DelSal et al., xe2x80x9cCell Cycle and Cancer: Critical Events at the G1 Restriction Point,xe2x80x9d Critical Rev. Oncogenesis, vol. 71 (1996), pp. 127-142). Genes encoding the CDK4-specific inhibitors of the p16 family frequently have deletions and mutations in familial melanoma, gliomas, leukemias, sarcomas, and pancreatic, non-small cell lung, and head and neck carcinomas (see Nobori et al., xe2x80x9cDeletions of the Cyclin-Dependent Kinase-4 Inhibitor Gene in Multiple Human Cancers,xe2x80x9d Nature, vol. 368 (1994), pp. 753-756). Amplification and/or overexpression of cyclin E has also been observed in a wide variety of solid tumors, and elevated cyclin E levels have been correlated with poor prognosis. In addition, the cellular levels of the CDK inhibitor p27, which acts as both a substrate and inhibitor of CDK2/cyclin E, are abnormally low in breast, colon, and prostate cancers, and the expression levels of p27 are inversely correlated with the stage of disease (see Loda et al., xe2x80x9cIncreased Proteasome-dependent Degradation of the Cyclin-Dependent Kinase Inhibitor p27 in Aggressive Colorectal Carcinomas,xe2x80x9d Nature Medicine, vol. 3 (1997), pp. 231-234). Recently there is evidence that CDK4/cyclin D might sequester p27, as reviewed in Sherr, et al., Genes Dev., Vol. 13 (1999), pp. 1501-1512. The p21 proteins also appear to transmit the p53 tumor-suppression signal to the CDKs; thus, the mutation of p53 in approximately 50% of all human cancers may indirectly result in deregulation of CDK activity.
The emerging data provide strong validation for the use of compounds inhibiting CDKs, and CDK4 and CDK2 in particular, as anti-proliferative therapeutic agents. Certain biomolecules have been proposed for this purpose. For example, U.S. Pat. No. 5,621,082 to Xiong et al. discloses nucleic acid encoding of inhibitors of CDK6, and WO 99/06540 for CDK""s. Peptides and peptidomimetic inhibitors are described in European Patent Publication No. 0 666 270 A2, Bandara, et al., Nature Biotechnology, Vol. 15 (1997), pp. 896-901 and Chen, et al., Proceedings of the National Academy of Science, USA, Vol. 96 (1999), pp. 4325-4329. Peptide aptamers were identified from screening in Cohen, et al., Proc. Natl. Acad. Sci. U. S. A., Vol. 95 (1998), pp. 14272-14277. Several small molecules have been identified as CDK inhibitors (for recent reviews, see Webster, xe2x80x9cThe Therapeutic Potential of Targeting the Cell Cycle,xe2x80x9d Exp. Opin. Invest. Drugs, vol. 7 (1998), pp. 865-887, and Stover, et al., xe2x80x9cRecent advances in protein kinase inhibition: current molecular scaffolds used for inhibitor synthesis,xe2x80x9d Current Opinion in Drug Discovery and Development, Vol. 2 (1999), pp. 274-285). The flavone flavopiridol displays modest selectivity for inhibition of CDKs over other kinases, but inhibits CDK4, CDK2, and CDK1 equipotently, with IC50s in the 0.1-0.3 xcexcM range. Flavopiridol is currently in Phase II clinical trials as an oncology chemotherapeutic (Sedlacek et al., xe2x80x9cFlavopiridol (L86-8275; NSC 649890), A New Kinase Inhibitor for Tumor Therapy,xe2x80x9d lnt J. Oncol., vol. 9 (1996), pp. 1143-1168). Analogs of flavopiridol are the subject of other publications, for example, U.S. Pat. No. 5,733,920 to Mansuri et al. (International Publication No. WO 97/16447) and International Publication Nos. WO 97/42949, and WO 98/17662. Results with purine-based derivatives are described in Schow et al., Bioorg. Med. Chem. Lett., vol. 7 (1997), pp. 2697-2702; Grant et al., Proc. Amer. Assoc. Cancer Res,. vol. 39 (1998), Abst. 1207; Legravend et al., Bioorg. Med. Chem. Leff., vol. 8 (1998), pp. 793-798; Gray et al., Science, vol. 281 (1998), pp. 533-538; Chang, et al., Chemistry and Biology, Vol. 6 (1999), pp. 361-375, WO 99/ 02162, WO 99/43675, and WO 99/43676. In addition, the following publications disclose certain pyrimidines that inhibit cyclin-dependent kinases and growth-factor mediated kinases: International Publication No. WO 98/33798; Ruetz et al., Proc. Amer. Assoc. Cancer Res,. vol. 39 (1998), Abst. 3796; and Meyer et al., Proc. Amer. Assoc. Cancer Res., vol. 39 (1998), Abst. 3794.
Benzensulfonamides that block cells in G1 are in development by Eisai, see Owa, et al., J. Med. Chem., Vol. 42 (1999), pp. 3789-3799. An oxindole CDK inhibitor is in development by Glaxo-Wellcome, see Luzzio, et al., Proc. Amer. Assoc. Cancer Res., Vol. (1999), Abst. 4102 and WO99/15500. Paullones were found in collaboration with the NCI, Schultz, et al., J. Med. Chem., Vol. (1999), pp. 2909-2919. Indenopyrazoles are described in WO99/17769 and by Seitz, et al, 218th ACS Natl. Mtg. (Aug. 22-26, 1999, New Orleans), Abst MEDI 316. Aminothiazoles are used in WO99/24416 and WO99/21845.
CHK1 is another protein kinase. CHK 1 plays an important role as a checkpoint in cell cycle progression. Checkpoints are control systems that coordinate cell cycle progression by influencing the formation, activation and subsequent inactivation of the cyclin-dependent kinases. Checkpoints prevent cell cycle progression at inappropriate times, maintain the metabolic balance of cells while the cell is arrested, and in some instances can induce apoptosis (programmed cell death) when the requirements of the checkpoint have not been met. See, e.g., O""Connor, Cancer Surveys, 29, 151-182 (1997); Nurse, Cell, 91, 865-867 (1997); Hartwell et al., Science, 266, 1821-1828 (1994); Hartwell et al., Science, 246, 629-634 (1989).
One series of checkpoints monitors the integrity of the genome and, upon sensing DNA damage, these xe2x80x9cDNA damage checkpointsxe2x80x9d block cell cycle progression in G1 and G2 phases, and slow progression through S phase. O""Connor, Cancer Surveys, 29, 151-182 (1997); Hartwell et al., Science, 266, 1821-1828 (1994). This action enables DNA repair processes to complete their tasks before replication of the genome and subsequent separation of this genetic material into new daughter cells takes place. Importantly, the most commonly mutated gene in human cancer, the p53 tumor suppressor gene, produces a DNA damage checkpoint protein that blocks cell cycle progression in G1 phase and/or induces apoptosis (programmed cell death) following DNA damage. Hartwell et al., Science, 266, 1821-1828 (1994). The p53 tumor suppressor has also been shown to strengthen the action of a DNA damage checkpoint in G2 phase of the cell cycle. See, e.g., Bunz et al., Science, 28, 1497-1501 (1998); Winters et al., Oncogene, 17, 673-684 (1998); Thompson, Oncogene, 15, 3025-3035 (1997).
Given the pivotal nature of the p53 tumor suppressor pathway in human cancer, therapeutic interventions that exploit vulnerabilities in p53-defective cancer have been actively sought. One emerging vulnerability lies in the operation of the G2 checkpoint in p53 defective cancer cells. Cancer cells, because they lack G1 checkpoint control, are particularly vulnerable to abrogation of the last remaining barrier protecting them from the cancer killing effects of DNA-damaging agents: the G2 checkpoint. The G2 checkpoint is regulated by a control system that has been conserved from yeast to humans. Important in this conserved system is a kinase, CHK1, which transduces signals from the DNA-damage sensory complex to inhibit activation of the cyclin B/Cdc2 kinase, which promotes mitotic entry. See, e.g., Peng et al., Science, 277, 1501-1505 (1997); Sanchez et al., Science, 277, 1497-1501 (1997). Inactivation of CHK1 has been shown to both abrogate G2 arrest induced by DNA damage inflicted by either anticancer agents or endogenous DNA damage, as well as result in preferential killing of the resulting checkpoint defective cells. See, e.g., Nurse, Cell, 91, 865-867 (1997); Weinert, Science, 277, 1450-1451 (1997); Walworth et al., Nature, 363, 368-371 (1993); and AI-Khodairy et al., Molec. Biol. Cell, 5, 147-160 (1994).
Selective manipulation of checkpoint control in cancer cells could afford broad utilization in cancer chemotherapeutic and radiotherapy regimens and may, in addition, offer a common hallmark of human cancer xe2x80x9cgenomic instabilityxe2x80x9d to be exploited as the selective basis for the destruction of cancer cells. A number of factors place CHK1 as a pivotal target in DNA-damage checkpoint control. The elucidation of inhibitors of this and functionally related kinases such as CDS1/CHK2, a kinase recently discovered to cooperate with CHK1 in regulating S phase progression (see Zeng et al., Nature, 395, 507-510 (1998); Matsuoka, Science, 282, 1893-1897 (1998)), could provide valuable new therapeutic entities for the treatment of cancer.
Another group of kinases are the tyrosine kinases. Tyrosine kinases can be of the receptor type (having extracellular, transmembrane and intracellular domains) or the non-receptor type (being wholly intracellular). At least one of the non-receptor protein tyrosine kinases, namely, LCK, is believed to mediate the transduction in T-cells of a signal from the interaction of a cell-surface protein (Cd4) with a cross-linked anti-Cd4 antibody. A more detailed discussion of non-receptor tyrosine kinases is provided in Bolen, Oncogene, 8, 2025-2031 (1993), which is incorporated herein by reference.
In addition to its role in cell-cycle control, protein kinases also play a crucial role in angiogenesis, which is the mechanism by which new capillaries are formed from existing vessels. When required, the vascular system has the potential to generate new capillary networks in order to maintain the proper functioning of tissues and organs. In the adult, however, angiogenesis is fairly limited, occurring only in the process of wound healing and neovascularization of the endometrium during menstruation. See Merenmies, J., Parada, L. F., Henkemeyer, M., Cell Growth and Differentiation, 8, 3-10 (1997). On the other hand, unwanted angiogenesis is a hallmark of several diseases, such as retinopathies, psoriasis, rheumatoid arthritis, age-related macular degeneneration, and cancer (solid tumors). Folkman, Nature Med., 1, 27-31 (1995). Protein kinases which have been shown to be involved in the angiogenic process include three members of the growth factor receptor tyrosine kinase family: VEGF-R2 (vascular endothelial growth factor receptor 2, also know as KDR (kinase insert domain receptor) and as FLK-1); FGF-R (fibroblast growth factor receptor); and TEK (also known as Tie-2).
VEGF-R2, which is expressed only on endothelial cells, binds the potent angiogenic growth factor VEGF and mediates the subsequent signal transduction through activation of its intracellular kinase activity. Thus, it is expected that direct inhibition of the kinase activity of VEGF-R2 will result in the reduction of angiogenesis even in the presence of exogenous VEGF (see Strawn et al., Cancer Research, 56, 3540-3545 (1996)), as has been shown with mutants of VEGF-R2 which fail to mediate signal transduction. Millauer et al., Cancer Research, 56, 1615-1620 (1996). Furthermore, VEGF-R2 appears to have no function in the adult beyond that of mediating the angiogenic activity of VEGF. Therefore, a selective inhibitor of the kinase activity of VEGF-R2 would be expected to exhibit little toxicity.
Similarly, FGF-R binds the angiogenic growth factors aFGF and bFGF and mediates subsequent intracellular signal transduction. Recently, it has been suggested that growth factors such as bFGF may play a critical role in inducing angiogenesis in solid tumors that have reached a certain size. Yoshiji et al., Cancer Research, 57, 3924-3928 (1997). Unlike VEGF-R2, however, FGF-R is expressed in a number of different cell types throughout the body and may or may not play important roles in other normal physiological processes in the adult. Nonetheless, systemic administration of a small molecule inhibitor of the kinase activity of FGF-R has been reported to block bFGF-induced angiogenesis in mice without apparent toxicity. Mohammad et al., EMBO Journal, 17, 5996-5904 (1998).
TEK (also known as Tie-2) is another receptor tyrosine kinase expressed only on endothelial cells which has been shown to play a role in angiogenesis. The binding of the factor angiopoietin-1 results in autophosphorylation of the kinase domain of TEK and results in a signal transduction process which appears to mediate the interaction of endothelial cells with peri-endothelial support cells, thereby facilitating the maturation of newly formed blood vessels. The factor angiopoietin-2, on the other hand, appears to antagonize the action of angiopoietin-1 on TEK and disrupts angiogenesis. Maisonpierre et al., Science, 277, 55-60 (1997).
As a result of the above-described developments, it has been proposed to treat angiogenesis by the use of compounds inhibiting the kinase activity of VEGF-R2, FGF-R, and/or TEK. For example, WIPO International Publication No. WO 97/34876 discloses certain cinnoline derivatives that are inhibitors of VEGF-R2, which may be used for the treatment of disease states associated with abnormal angiogenesis and/or increased vascular permeability such as cancer, diabetes, psoriosis, rheumatoid arthritis, Kaposi""s sarcoma, haemangioma, acute and chronic nephropathies, atheroma, arterial restinosis, autoimmune diseases, acute inflammation and ocular diseases with retinal vessel proliferation. In addition to the protein kinases identified above, many other protein kinases have been considered to be therapeutic targets, and numerous publications disclose inhibitors of kinase activity, as reviewed in the following: McMahon et al., Current Opinion in Drug Discovery and Development, 1, 131-146 (1998); Strawn et al., Exp. Opin. Invest. Drugs, 7, 553-573 (1998).
There is still a need, however, for other small-molecule compounds that may be readily synthesized and are potent inhibitors of cell proliferation, for example, inhibitors of one or more protein kinases, such as CHK1, VEGF, CDKs or CDK/cyclin complexes. Because CDK4 may serve as a general activator of cell division in most cells, and because complexes of CDK4/cyclin D and CDK2/cyclin E govern the early G1 phase of the cell cycle, there is a need for effective and specific inhibitors of CDK4 and/or CDK2 for treating one or more types of tumors.
An object of the invention is to provide potent anti-proliferative agents. Accordingly, one object of the invention is to attain compounds and drug compositions that inhibit the activity of one or more kinases, such as CDKs, VEGF, and CHK-1, or cyclin complexes thereof. A further object is to provide an effective method of treating cancer indications through kinases inhibition, such as through inhibition of VEGF, CHK-1, CDK4 or CDK4/D-type cyclin complexes and/or CDK2 or CDK2/E-type cyclin complexes. Another object is to achieve pharmaceutical compositions containing compounds effective to block the transition of cancer cells into their proliferative phase. These and other objects and advantages of the invention, which will become apparent in light of the detailed description below, are achieved through use of cell-cycle control agents of the invention described below.
According to these objectives, there is provided in accordance with the present invention a compound represented by the Formula I 
wherein:
R1 is a substituted or unsubstituted alkyl, aryl, heteroaryl, carbocycle, or heterocycle group, or 
xe2x80x83wherein R4 is H or lower alkyl, and X is a substituted or unsubstituted alkyl, aryl, heteroaryl, carbocycle, or heterocycle group; and
R2 is a substituted or unsubstituted alkyl, aryl, heteroaryl, carbocycle, or heterocycle group, or 
xe2x80x83wherein R4 is H or lower alkyl, and X is a substituted or unsubstituted aryl, heteroaryl, carbocycle, or heterocycle group; or
a pharmaceutically acceptable salt of a compound of the Formula I; or a prodrug or pharmaceutically active metabolite of a compound of the Formula I, or a pharmaceutically acceptable salt of the prodrug or metabolite. According to these objectives, there is also provided a compound represented by Formula II: 
wherein
Rxe2x80x21 is a substituted or unsubstituted alkyl, aryl, heteroaryl, carbocycle, heterocycle, 
or 
group,
wherein each R4 is individually H or lower alkyl and X is a substituted or unsubstituted alkyl, aryl, heteroaryl, carbocycle, or heterocycle group; and
Rxe2x80x22 is a substituted or unsubstituted amino, nitro, alkenyl, alkyl, aryl, heteroaryl, carbocycle, heterocycle, 
or 
group,
xe2x80x83wherein R4 is independently H or lower alkyl, and X is a substituted or unsubstituted aryl, heteroaryl, carbocycle, or
heterocycle group; or
a pharmaceutically acceptable salt of a compound of the Formula II; or a prodrug or pharmaceutically active metabolite of a compound of the Formula II, or a pharmaceutically acceptable salt of the prodrug or metabolite thereof. There is also provided in accordance with the invention, a pharmaceutical composition comprising:
(a) a cell-cycle control agent selected from:
(i) a compound of the Formula I or II,
(ii) a pharmaceutically acceptable salt of a compound of the Formula I or II; or
(iii) a prodrug or pharmaceutically active metabolite of a compound of the Formula I or II, or a pharmaceutically acceptable salt of the prodrug or metabolite; and
(b) a pharmaceutically acceptable carrier.
The invention also provides methods for making compounds of Formula I and II.
There is further provided in accordance with the invention, a method of using a compound as a cell-cycle control agent for treating a disease or disorder mediated by inhibition of kinase comprising administering to a patient in need thereof, a compound of Formula I or II, or a pharmaceutically acceptable salt of a compound of the Formula I or II; or a prodrug or pharmaceutically active metabolite of a compound of the Formula I or II, or a pharmaceutically acceptable salt of the metabolite or prodrug.
The invention further provides a method of treating mycotic infection, malignancies or cancer as well as other disease states associated with unwanted angiogenesis and/or cellular proliferation, comprising administering effective amounts of a compound of Formula I or II or a pharmaceutically acceptable salt of a compound of the Formula I or II; or a prodrug or pharmaceutically active metabolite of a compound of the Formula I or II, or a pharmaceutically acceptable salt of the metabolite or prodrug, to a patient in need of such treatment.
The invention also provides a method of modulating and/or inhibiting kinase activity by administering a compound of the Formula I or II or a pharmaceutically acceptable salt of a compound of the Formula I or II; or a prodrug or pharmaceutically active metabolite of a compound of the Formula I or II, or a pharmaceutically acceptable salt of the metabolite or prodrug, to a patient in need thereof.
There is also provided in accordance with the invention, a pharmaceutical composition containing a compound of the Formula I or II or a pharmaceutically acceptable salt of a compound of the Formula I or II; or a prodrug, or pharmaceutically active metabolite of a compound of the Formula I or II, or a pharmaceutically acceptable salt of the metabolite or prodrug, and the therapeutic use of the composition in treating diseases mediated by kinase activity, such as cancer, as well as other disease states associated with unwanted angiogenesis and/or cellular proliferation, such as diabetic retinopathy, neovascular glaucoma, rheumatoid arthritis, and psoriasis.
For the pharmaceutical composition and method aspects of the invention, R1 can also be hydrogen, in Formula I and II.
The inventive agents and compositions containing such agents may be useful in treating various disorders or disease states associated with uncontrolled or unwanted cellular proliferation, such as cancer, autoimmune disorders, viral diseases, fungal diseases, neurodegenerative disorders, and cardiovascular diseases. Thus, the invention is also directed to methods of treating such diseases by administering an effective amount of the inventive agent.
Other aspects, advantages, and features of the invention will become apparent from the detailed description below.
The compounds and compositions of the present invention, are useful as anti-proliferative agents and as inhibitors of mammalian kinase complexes, insect kinase or fungal kinase complexes. For example, VEGF, CHK-1, and/or CDK complexes can be inhibited. Such compounds and compositions are also useful for controlling proliferation, differentiation, and/or apoptosis.
Examples of R1, R2, Rxe2x80x21, and Rxe2x80x22 preferred in compounds of Formula I or II groups are set forth below: 
Preferably R1 and Rxe2x80x21 are: 
wherein Y is CH or N or CR3, X is as defined above and R3 is H, or one or more substituents located on the ring, such as a substituted or unsubstituted alkyl, alkenyl, aryl, heteroaryl, carbocycle, heterocycle, hydroxy, halogen, alkoxy, aryloxy, heteroaryloxy, thioalkyl, thioaryl, thioacyl, thioheteroaryl or amino; or 
xe2x80x83wherein the two Y""s can be the same or different.
In those embodiments, wherein R1 or Rxe2x80x21 is 
there can be one or more R3 substituents on the phenyl ring.
More preferably, R1 and Rxe2x80x21 are substituted or unsubstituted 
wherein the R3 groups are as defined above. Also, two R3""s together with an adjacent nitrogen can form a heteroaryl or heterocycle ring.
Preferably, R2 and Rxe2x80x22 are unsubstituted or substituted phenyl or 
wherein R4 is H or lower alkyl, and X is a substituted or unsubstituted group selected from alkyl, aryl, heteroaryl, carbocycle, or heterocycle.
Other preferred R2 and Rxe2x80x22 groups are substituted or unsubstituted heteroaryls such as 
Other preferred R2 and Rxe2x80x22 groups are 
where R3 is as defined above.
Especially preferred substituents for the phenyl of R2 include fluorine, chlorine, hydroxyl, or an alkoxy group, such as methoxy. Examples of preferred R groups, X, and Y groups are found in the exemplary compounds that follow.
Y is preferably nitrogen.
X is preferably aryl, heteroaryl, carbocycle, or heterocycle, most preferably phenyl.
R2 and Rxe2x80x22 can also be an amino (xe2x88x92NRxe2x80x2Rxe2x80x3), wherein Rxe2x80x2 and Rxe2x80x3 are independently as defined for R3 above, and together with an adjacent nitrogen can form a ring.
R4 is preferably hydrogen, or can be a lower alkyl having 1-6 carbon atoms, which may be substituted or unsubstituted. The two R4""s can be the same or different.
Other preferred R1, R2, Rxe2x80x21, and Rxe2x80x22 groups are found in the exemplary compounds that follow.
Any desired alkyl group can be used, e.g., as R1 or R2 or Rxe2x80x21 or Rxe2x80x22 or R3 or X. The alkyl group can be a straight- or branched-chain alkyl group having one to twelve carbon atoms. Exemplary alkyl groups include methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, tert-pentyl, hexyl, isohexyl, and the like. The alkyl can be substituted or unsubstituted. Preferred substituted alkyls include fluoromethyl, difluoromethyl, trifluoromethyl, 2-fluoroethyl, 3-fluoropropyl, hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, and the like.
Any desired aryl, heteroaryl, carbocycle, or heterocycle group can be used as, e.g., R1 or R2 or Rxe2x80x21 or Rxe2x80x22 or R3 or X. The groups can be fused or non-fused, monocyclic or polycyclic.
Preferred aryl and heteroaryl groups include monocyclic and polycyclic unsaturated or aromatic ring structures, with xe2x80x9carylxe2x80x9d referring to those that are carbocycles and xe2x80x9cheteroarylxe2x80x9d referring to those that are heterocycles. Examples of ring structures include phenyl, naphthyl, 1,2,3,4-tetrahydronaphthyl, furyl, thienyl, pyrrolyl, pyridyl, pyridinyl, pyrazolyl, imidazolyl, pyrazinyl, pyridazinyl, 1,2,3-triazinyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, 1-H-tetrazol-5-yl, indolyl, quinolinyl, benzothiophenyl (thianaphthenyl), furanyl, thiophenyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, isoquinolinyl, acridinyl, pyrimidinyl, benzimidazolyl, benzofuranyl, and the like.
Preferred carbocyclic groups include those having from three to twelve carbon atoms, including bicyclic and tricyclic cycloalkyl structures. Preferred carbocyclic groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like.
Preferred heterocyclic groups include saturated rings containing carbon atoms, for example containing 4 or 5 ring carbon atoms, and at least one heteroatom selected from nitrogen, oxygen and sulfur, and having no unsaturation. Preferred heterocyclic groups include pyrrolidinyl, piperidinyl, thiazinyl, and morpholinyl.
R1, R2, R3, Y, X, and other R groups can be unsubstituted or substituted with any desired substituent or substituents that do not adversely affect the desired activity of the compound. Examples of preferred substituents are those found in the exemplary compounds that follows, as well as halogen (chloro, iodo, bromo, or fluoro); C1-6-alkyl; C1-6-alkenyl; C1-6-alkynyl; hydroxyl; C1-6 alkoxyl; amino; nitro; thiol; thioether; imine; cyano; amido; phosphonato; phosphine; carboxyl; thiocarbonyl; sulfonyl; sulfonamide; ketone; aldehyde; ester; oxygen (xe2x95x90O); haloalkyl (e.g., trifluoromethyl); carbocyclic cycloalkyl, which may be monocyclic or fused or non-fused polycyclic (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl), or a heterocycloalkyl, which may be monocyclic or fused or non-fused polycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, or thiazinyl); carbocyclic or heterocyclic, monocyclic or fused or non-fused polycyclic aryl (e.g., phenyl, naphthyl, pyrrolyl, indolyl, furanyl, thiophenyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridinyl, quinolinyl, isoquinolinyl, acridinyl, pyrazinyl, pyridazinyl, pyrimidinyl, benzimidazolyl, benzothiophenyl, or benzofuranyl); amino (primary, secondary, or tertiary); nitro; thiol; thioether, 0-lower alkyl; 0-aryl, aryl; aryl-lower alkyl; CO2CH3; CONH2; OCH2CONH2; NH2; SO2NH2; OCHF2; CF3; OCF3; an Such moieties may also be optionally substituted by a fused-ring structure or bridge, for example OCH2xe2x80x94O.
These substituents may optionally be further substituted with a substituent selected from such groups.
Preferred compounds are shown in the examples that follow as well as: 
The present invention also relates to intermediates useful in the preparation of compounds of Formula I or II. A particularly preferred intermediate has the structure 
Another preferred intermediate has the structure 
Another preferred intermediate has the structure 
In place of SEM, in the above three intermediates, other known protecting groups, such as benzyloxycarbonyl (CBZ), tert-butoxycarbonyl (BOC), tetra hydropyranyl (THP), and fluorene-9-methyloxycarbonyl (FMOC), can be used.
Other preferred intermediates include 
The abbreviations xe2x80x9cSEMxe2x80x9d and xe2x80x9cPMBxe2x80x9d refer to (trimethyl silyl) ethoxy methyl and p-methoxybenzyl, respectively.
A preferred intermediate has the structure 
wherein PG is a protecting group, T is a reactive group such as a substituted or unsubstituted boron, halogen, NO2, or NH2 group, and Txe2x80x2 is a reactive group such as CHO, CO2H, CO2R3, CONR3R3, where R3 groups are as defined above.
Pharmaceutical compositions according to the invention may, alternatively or in addition to a compound of the Formula I or II, comprise as an active ingredient a pharmaceutically acceptable salt of a compound of the Formula I or II, or a prodrug or pharmaceutically active metabolite of such a compound or salt or a salt of the prodrug or metabolite. Such compounds, salts, prodrugs, and metabolites are sometimes referred to herein collectively as xe2x80x9ccell-cycle control agents.xe2x80x9d
The term xe2x80x9cprodrugxe2x80x9d refers to a metabolic precursor of a compound of the Formula I or II (or a salt thereof) that is pharmaceutically acceptable. A prodrug may be inactive when administered to a subject but is converted in vivo to an active compound of the Formula I or II. The term xe2x80x9cactive metabolitexe2x80x9d refers to a metabolic product of a compound of the Formula I or II that is pharmaceutically acceptable and effective. Prodrugs and active metabolites of compounds of the Formula I or II may be determined using techniques known in the art.
Prodrugs and active metabolites of a compound may be identified using routine techniques known in the art. See, e.g., Bertolini et al., J. Med. Chem., 40, 2011-2016 (1997); Shan, et al., J. Pharm. Sci., 86 (7), 765-767; Bagshawe, Drug Dev. Res., 34, 220-230 (1995); Bodor, Advances in Drug Res., 13, 224-331 (1984); Bundgaard, Design of Prodrugs (Elsevier Press 1985); and Larsen, Design and Application of Prodrugs, Drug Design and Development (Krogsgaard-Larsen et al., eds., Harwood Academic Publishers, 1991).
Within the invention it is understood that a compound of Formula I or II may exhibit the phenomenon of tautomerism and that the formula drawings within this specification represent only one of the possible tautomeric forms. It is to be understood that the invention encompasses any tautomeric form which modulates and/or inhibits kinase activity and is not to be limited merely to any one tautomeric form utilized within the formula drawings.
Some of the inventive compounds may exist as single stereoisomers (i.e., essentially free of other stereoisomers), racemates, and/or mixtures of enantiomers and/or diastereomers. All such single stereoisomers, racemates and mixtures thereof are intended to be within the scope of the present invention. Preferably, the inventive compounds that are optically active are used in optically pure form.
As generally understood by those skilled in the art, an optically pure compound having one chiral center (i.e., one asymmetric carbon atom) is one that consists essentially of one of the two possible enantiomers (i.e., is enantiomerically pure), and an optically pure compound having more than one chiral center is one that is both diastereomerically pure and enantiomerically pure. Preferably, the compounds of the present invention are used in a form that is at least 90% optically pure, that is, a form that contains at least 90% of a single isomer (80% enantiomeric excess (xe2x80x9ce.e.xe2x80x9d) or diastereomeric excess (xe2x80x9cd.e.xe2x80x9d)), more preferably at least 95% (90% e.e. or d.e.), even more preferably at least 97.5% (95% e.e. or d.e.), and most preferably at least 99% (98% e.e. or d.e.).
Additionally, Formulas I and II are intended to cover solvated as well as unsolvated forms of the identified structures. For example, Formulas I and II include compounds of the indicated structure in both hydrated and non-hydrated forms. Other examples of solvates include the structures in combination with isopropanol, ethanol, methanol, DMSO, ethyl acetate, acetic acid, or ethanolamine.
xe2x80x9cA pharmaceutically acceptable saltxe2x80x9d is intended to mean a salt that retains the biological effectiveness of the free acids and bases of the specified compound and that is not biologically or otherwise undesirable. A compound of the invention may possess a sufficiently acidic, a sufficiently basic, or both functional groups, and accordingly react with any of a number of inorganic or organic bases, and inorganic and organic acids, to form a pharmaceutically acceptable salt. Exemplary pharmaceutically acceptable salts include those salts prepared by reaction of the compounds of the present invention with a mineral or organic acid or an inorganic base, such as salts including sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, phosphates, monohydrogenphosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caproates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-dioates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, sulfonates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, xcex3-hydroxybutyrates, glycollates, tartrates, methane-sulfonates, propanesulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates, and mandelates.
If the inventive compound is a base, the desired pharmaceutically acceptable salt may be prepared by any suitable method available in the art, for example, treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, or with an organic acid, such as acetic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyrovic acid, oxalic acid, glycolic acid, salicylic acid, a pyranosidyl acid, such as glucuronic acid or galacturonic acid, an alpha-hydroxy acid, such as citric acid or tartaric acid, an amino acid, such as aspartic acid or glutamic acid, an aromatic acid, such as benzoic acid or cinnamic acid, a sulfonic acid, such as p-toluenesulfonic acid or ethanesulfonic acid, or the like. If the inventive compound is an acid, the desired pharmaceutically acceptable salt may be prepared by any suitable method, for example, treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal hydroxide or alkaline earth metal hydroxide, or the like. Illustrative examples of suitable salts include organic salts derived from amino acids, such as glycine and arginine, ammonia, primary, secondary, and tertiary amines, and cyclic amines, such as piperidine, morpholine and piperazine, and inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum and lithium.
In the case of agents that are solids, it is understood by those skilled in the art that the inventive compounds and salts may exist in different crystal or polymorphic forms, all of which are intended to be within the scope of the present invention and specified formulas.
Cell-cycle control agents in accordance with the invention are useful as pharmaceuticals for treating proliferative disorders in mammals, especially humans, marked by unwanted proliferation of endogenous tissue. Compounds of the Formula I or II may be used for treating subjects having a disorder associated with excessive cell proliferation, e.g., cancers, psoriasis, immunological disorders involving undesired proliferation of leukocytes, and restenosis and other smooth-muscle disorders. Furthermore, such compounds may be used to prevent de-differentiation of post-mitotic tissue and/or cells.
Diseases or disorders associated with uncontrolled or abnormal cellular proliferation include, but are not limited to, the following:
a variety of cancers, including, but not limited to, carcinoma, hematopoietic tumors of lymphoid lineage, hematopoietic tumors of myeloid lineage, tumors of mesenchymal origin, tumors of the central and peripheral nervous system and other tumors including melanoma, seminoma and Kaposi""s sarcoma and the like.
a disease process which features abnormal cellular proliferation, e.g., benign prostatic hyperplasia, familial adenomatosis polyposis, neuro-fibromatosis, atherosclerosis, pulmonary fibrosis, arthritis, psoriasis, glomerulonephritis, restenosis following angioplasty or vascular surgery, hypertrophic scar formation, inflammatory bowel disease, transplantation rejection, endotoxic shock, and fungal infections.
defective apoptosis-associated conditions, such as cancers (including but not limited to those types mentioned hereinabove), viral infections (including but not limited to herpesvirus, poxvirus, Epstein-Barr virus, Sindbis virus and adenovirus), prevention of AIDS development in HIV-infected individuals, autoimmune diseases (including but not limited to systemic lupus erythematosus, rheumatoid arthritis, psoriasis, autoimmune mediated glomerulonephritis, inflammatory bowel disease and autoimmune diabetes mellitus), neurodegenerative disorders (including but not limited to Alzheimer""s disease, amyotrophic lateral sclerosis, retinitis pigmentosa, Parkinson""s disease, AIDS-related dementia, spinal muscular atrophy and cerebellar degeneration), myelodysplastic syndromes, aplastic anemia, ischemic injury associated with myocardial infarctions, stroke and reperfusion injury, arrhythmia, atherosclerosis, toxin-induced or alcohol related liver diseases, hematological diseases (including but not limited to chronic anemia and aplastic anemia), degenerative diseases of the musculoskeletal system (including but not limited to osteroporosis and arthritis), aspirin-sensitive rhinosinusitis, cystic fibrosis, multiple sclerosis, kidney diseases and cancer pain.
The active agents of the invention may also be useful in the inhibition of the development of invasive cancer, tumor angiogenesis and metastasis.
Moreover, the active agents of the invention, for example, as inhibitors of the CDKs, can modulate the level of cellular RNA and DNA synthesis and therefore are expected to be useful in the treatment of viral infections such as HIV, human papilloma virus, herpes virus, Epstein-Barr virus, adenovirus, Sindbis virus, pox virus and the like.
Compounds and compositions of the invention inhibit the kinase activity of, for example, CDK/cyclin complexes, such as those active in the G0 or G1 stage of the cell cycle, e.g., CDK2, CDK4, and/or CDK6 complexes.
The specific dosage amount of a cell-cycle control agent being administered to obtain therapeutic or inhibitory effects may be determined in a manner known in the art according to the particular circumstances surrounding the case, including, e.g., the specific agent being administered, the route of administration, the condition being treated, and the subject or host being treated. An exemplary total daily dose of a cell-cycle control agent, which may be administered in single or multiple doses, contains a dosage level of from about 0.01 mg/kg body weight to about 50 mg/kg body weight.
The cell-cycle control agents of the invention may be administered by any of a variety of suitable routes, such as orally, rectally, transdermally, subcutaneously, intravenously, intramuscularly, or intranasally. The cell-cycle control agents are preferably formulated into compositions suitable for the desired routes before being administered.
A pharmaceutical composition or preparation according to the invention comprises an effective amount of a cell-cycle control agent, optionally one or more other active agents, and a pharmaceutically acceptable carrier, such as a diluent or excipient for the agent; when the carrier serves as a diluent, it may be a solid, semi-solid, or liquid material acting as a vehicle, excipient, or medium for the active ingredient(s). Compositions according to the invention may be made by admixing the active ingredient(s) with a carrier, or diluting it with a carrier, or enclosing or encapsulating it within a carrier, which may be in the form of a capsule, sachet, paper container, or the like. Exemplary ingredients, in addition to one or more cell-cycle control agents and any other active ingredients, include Avicel (microcrystalline cellulose), starch, lactose, calcium sulfate dihydrate, terra alba, sucrose, talc, gelatin, agar, pectin, acacia, magnesium stearate, stearic acid, peanut oil, olive oil, glyceryl monostearate, Tween 80 (polysorbate 80), 1,3-butanediol, cocoa butter, beeswax, polyethylene glycol, propylene glycol, sorbitan monostearate, polysorbate 60, 2-octyldodecanol, benzyl alcohol, glycine, sorbic acid, potassium sorbate, disodium hydrogen phosphate, sodium chloride, and water.
The compositions may be prepared in any of a variety of forms suitable for the desired mode of administration. For example, pharmaceutical compositions may be prepared in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as solids or in liquid media), ointments (e.g., containing up to 10% by weight of a cell-cycle control agent), soft-gel and hard-gel capsules, suppositories, sterile injectable solutions, sterile packaged powders, and the like.
Similarly, the carrier or diluent may include time-delay or time-release material known in the art, such as glyceryl monostearate or glyceryl distearate alone or with a wax, ethylcellulose, hydroxypropylmethylcellulose, methylmethacrylate and the like.
A variety of pharmaceutical forms can be employed. Thus, if a solid carrier is used, the preparation can be tableted, placed in a hard gelatin capsule in powder or pellet form or in the form of a troche or lozenge. The amount of solid carrier may vary, but generally will be from about 25 mg to about 1 g. If a liquid carrier is used, the preparation can be in the form of syrup, emulsion, soft gelatin capsule, sterile injectable solution or suspension in an ampoule or vial or non-aqueous liquid suspension.
To obtain a stable water-soluble dose form, a pharmaceutically acceptable salt of an inventive agent is dissolved in an aqueous solution of an organic or inorganic acid, such as 0.3M solution of succinic acid or citric acid. If a soluble salt form is not available, the agent may be dissolved in a suitable cosolvent or combinations of cosolvents. Examples of suitable cosolvents include, but are not limited to, alcohol, propylene glycol, polyethylene glycol 300, polysorbate 80, gylcerin and the like in concentrations ranging from 0-60% of the total volume. A compound of Formula I or II may be dissolved in DMSO and diluted with water. The composition may also be in the form of a solution of a salt form of the active ingredient in an appropriate aqueous vehicle such as water or isotonic saline or dextrose solution.
The compositions of the invention may be manufactured in manners generally known for preparing pharmaceutical compositions, e.g., using conventional techniques such as mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing. Pharmaceutical compositions may be formulated in a conventional manner using one or more physiologically acceptable carriers, which may be selected from excipients and auxiliaries that facilitate processing of the active compounds into preparations which can be used pharmaceutically.
Proper formulation is dependent upon the route of administration chosen. For injection, the agents of the invention may be formulated into aqueous solutions, preferably in physiologically compatible buffers such as Hanks""s solution, Ringer""s solution, or physiological saline buffer. For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.
For oral administration, the compounds can be formulated readily by combining the active compounds with pharmaceutically acceptable carriers known in the art. Such carriers enable the compounds of the invention to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated. Pharmaceutical preparations for oral use can be obtained using a solid excipient in admixture with the active ingredient (agent), optionally grinding the resulting mixture, and processing the mixture of granules after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients include: fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; and cellulose preparations, for example, maize starch, wheat starch, rice starch; potato starch, gelatin, gum, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, methyl cellulose, or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as crosslinked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate.
Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, polyvinyl pyrrolidone, Carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active agents.
Pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with fillers such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate, and, optionally, stabilizers. In soft capsules, the active agents may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. All formulations for oral administration should be in dosages suitable for such administration. For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.
For administration intranasally or by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of gelatin for use in an inhaler or insufflator and the like may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.
The compounds may be formulated for parenteral administration by injection, e.g., by bolus injection or continuous infusion. Formulations for injection may be presented in unit-dosage form, e.g., in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents.
Pharmaceutical formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form. Additionally, suspensions of the active agents may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl oleate or triglycerides, or liposomes. Aqueous injection suspensions may contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.
For administration to the eye, the active agent is delivered in a pharmaceutically acceptable ophthalmic vehicle such that the compound is maintained in contact with the ocular surface for a sufficient time period to allow the compound to penetrate the corneal and internal regions of the eye, including, for example, the anterior chamber, posterior chamber, vitreous body, aqueous humor, vitreous humor, cornea, iris/ciliary, lens, choroid/retina and sclera. The pharmaceutically acceptable ophthalmic vehicle may be an ointment, vegetable oil, or an encapsulating material. A compound of the invention may also be injected directly into the vitreous and aqueous humor.
Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use. The compounds may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
The compounds may also be formulated as a depot preparation. Such long-acting formulations may be administered by implantation (for example, subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds may be formulated with suitable polymeric or hydrophobic materials (for example, as an emulsion in an acceptable oil) or ion-exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
A pharmaceutical carrier for hydrophobic compounds is a cosolvent system comprising benzyl alcohol, a nonpolar surfactant, a water-miscible organic polymer, and an aqueous phase. The cosolvent system may be a VPD co-solvent system. VPD is a solution of 3% w/v benzyl alcohol, 8% w/v of the nonpolar surfactant polysorbate 80, and 65% w/v polyethylene glycol 300, made up to volume in absolute ethanol. The VPD co-solvent system (VPD:5W) contains VPD diluted 1:1 with a 5% dextrose in water solution. This co-solvent system dissolves hydrophobic compounds well, and itself produces low toxicity upon systemic administration. Naturally, the proportions of a co-solvent system may be varied considerably without destroying its solubility and toxicity characteristics. Furthermore, the identity of the co-solvent components may be varied: for example, other low-toxicity nonpolar surfactants may be used instead of polysorbate 80; the fraction size of polyethylene glycol may be varied; other biocompatible polymers may replace polyethylene glycol, e.g. polyvinyl pyrrolidone; and other sugars or polysaccharides may be substituted for dextrose.
Alternatively, other delivery systems for hydrophobic pharmaceutical compounds may be employed. Liposomes and emulsions are known examples of delivery vehicles or carriers for hydrophobic drugs. Certain organic solvents such as dimethylsulfoxide also may be employed, although usually at the cost of greater toxicity. Additionally, the compounds may be delivered using a sustained-release system, such as semipermeable matrices of solid hydrophobic polymers containing the therapeutic agent. Various sustained-release materials have been established and are known by those skilled in the art. Sustained-release capsules may, depending on their chemical nature, release the compounds for a few weeks up to over 100 days. Depending on the chemical nature and the biological stability of the therapeutic reagent, additional strategies for protein stabilization may be employed.
The pharmaceutical compositions also may comprise suitable solid- or gel-phase carriers or excipients. Examples of such carriers or excipients include calcium carbonate, calcium phosphate, sugars, starches, cellulose derivatives, gelatin, and polymers such as polyethylene glycols.
Some of the compounds of the invention may be provided as salts with pharmaceutically compatible counter ions. Pharmaceutically compatible salts may be formed with many acids, including hydrochloric, sulfuric, acetic, lactic, tartaric, malic, succinic, etc. Salts tend to be more soluble in aqueous or other protonic solvents than are the corresponding free-base forms.
A pharmaceutical composition according to the invention comprises a cell-cycle control agent and, optionally, one or more other active ingredients, such as a known antiproliferative agent that is compatible with the cell-cycle control agent and suitable for the indication being treated.
The compounds are useful as anti-angiogenesis agents and as agents for modulating and/or inhibiting the activity of protein kinases, thus providing treatments for cancer or other diseases associated with cellular proliferation mediated by protein kinases.
Therapeutically effective amounts of the agents of the invention may be used to treat diseases mediated by modulation or regulation of protein kinases. An xe2x80x9ceffective amountxe2x80x9d is intended to mean that amount of an agent that, when administered to a mammal in need of such treatment, is sufficient to effect treatment for a disease mediated by the activity of one or more kinases. Thus, e.g., a therapeutically effective amount of a compound of the Formula I or II, salt, active metabolite or prodrug thereof is a quantity sufficient to modulate, regulate, or inhibit the activity of one or more kinases such that a disease condition which is mediated by that activity is reduced or alleviated.
xe2x80x9cTreatingxe2x80x9d is intended to mean at least the mitigation of a disease condition in a mammal, such as a human, that is affected, at least in part, by the activity of one or more kinases, and includes: preventing the disease condition from occurring in a mammal, particularly when the mammal is found to be predisposed to having the disease condition but has not yet been diagnosed as having it; modulating and/or inhibiting the disease condition; and/or alleviating the disease condition.
The inventive agents may be prepared using the reaction routes and synthesis schemes as described below, employing the techniques available in the art using starting materials that are readily available.
Exemplary general Schemes 1-6, shown below, can be used to make the compounds of the invention. 
The halogenated intermediate A can be obtained by standard diatozation of 5-amino indazole and treatment of the resulting diazonium salt with an appropriate halide salt, such as CuCl or Kl. Further halogenation to afford the 3-haloindazole B is achieved by treatment with a suitable base such as sodium hydroxide or potassium hydroxide and elemental halogen such as iodine. Intermediate B is protected using any number of suitable protecting groups and treated with a (preferably stoichiometric) alkyl or aryl boronic acid or ester and a suitable Pd catalyst, for example, Pd(PPh3)4, to affect selective reaction at the C-3 position. Further reaction with a second alkyl or aryl boronic acid or ester and a suitable Pd catalyst affords the desired 3,5-disubstituted intermediate E which is then deprotected to afford the final compound F. Deprotection conditions are consistent with the specific protecting group employed, for example, acidic conditions for removal of a THP protecting group. R1 and R2 are as defined above, and can be Rxe2x80x21 and Rxe2x80x22. 
The above alternative synthetic variation to Route 1 involves treatment of intermediate C wherein X is Cl with an alkyl ditin species, such as hexamethyl ditin, and an appropriate Pd catalyst, to afford intermediate G. Reaction of intermediate G with an alkyl or aryl halide and a suitable Pd catalyst provides the desired intermediate D which can be further elaborated as described above. 
Alternatively, as shown in Route 2 above, a 5-nitro indazole can be halogenated as described above for intermediate A, to afford nitro compound H, by treatment with a suitable base such as sodium hydroxide or potassium hydroxide and elemental halogen such as iodine to yield an intermediate I after standard protection with an appropriate protecting group. Treatment of intermediate I with an alkyl ditin species, such as hexamethyl ditin, and a suitable Pd catalyst, can afford intermediate J. Further reaction of nitro compound J with an alkyl or aryl boronic acid or ester and a suitable Pd catalyst affords the 3-substituted indazole K. Reduction of K with a suitable reducing agent, such as hydrogen with palladium catalyst or SnCl2, affords the amine. Diazotization of the resulting 5-amino indazole and treatment of the resulting diazonium salt with a suitable halide salt, such as CuCl or Kl affords intermediate halo compound L. Reaction of L with an alkyl or aryl boronic acid or ester and a suitable Pd catalyst affords the intermediate M which is deprotected as before to yield final compound F. R1 and R2 are as defined above, and can be Rxe2x80x21 and Rxe2x80x22. 
In Route 3 shown above, 3-carboxyindazole is activated to provide an active acylating species, such as with carbonyldiimidazole, which is then treated with a suitable alkoxy-alkyl amine, such N,N-dimethylhydroxylamine, to afford the amide Axe2x80x2. Selective halogenation of intermediate Axe2x80x2 with elemental halogen such as bromine or iodine and preferably with a catalyst such as bis(trifluoroacetoxy)iodosobenzene or bis(acetoxy) iodosobenzene yields the 5-halo indazole Bxe2x80x2. Protection of intermediate Bxe2x80x2 under standard conditions with a suitable protecting group such as PMB or THP affords protected amide Cxe2x80x2. Reduction of Cxe2x80x2 with an appropriate reductant such as lithium aluminum hydride or an equivalent hydride reducing agent yields key intermediate aldehyde Dxe2x80x2. R3 is as defined above, and is preferably substituted or unsubstituted alkyl, preferably lower alkyl. 
In Route 4 shown above, intermediate Dxe2x80x2 is reacted with a substituted diamine Bxe2x80x3 and a suitable oxidizing agent such as sulfur to afford the benzimidazole Cxe2x80x3. Conversion of compound Cxe2x80x3 to the corresponding borinate ester Dxe2x80x3 is accomplished by reacting with a suitable diboron species, such as dipinacolatodiboron, or other electrophilic source of boron, with an appropriate palladium catalyst. Intermediate Dxe2x80x3 is further reacted with a halogenated aryl or alkyl halide under palladium catalysis to give 5-substituted indazole intermediate Exe2x80x3, which after appropriate deprotection affords the final compound Hxe2x80x3.
Alternatively, starting compound Dxe2x80x2 is reacted with a suitable diboron species, such as bis(pinacolato)diboron, or other suitable electrophilic source of boron, and an appropriate palladium catalyst to give boron ester Fxe2x80x3. Elaboration of compound Fxe2x80x3 into intermediate Dxe2x80x3 is accomplished as described before for intermediate Dxe2x80x2.
Another alternative conversion can be accomplished by reacting intermediate aldehyde Fxe2x80x2 with a substituted aryl or alkyl halide to provide R2 with a palladium catalyst to afford Gxe2x80x3 which is further reacted with a substituted diamine Bxe2x80x3 and a suitable oxidizing agent such as sulfur to afford the benzimidazole Exe2x80x3. Deprotection as before yields final compound Hxe2x80x3. R2 is as defined above and can be Rxe2x80x22. R3 is as defined above.
Yet another preparation of intermediate Exe2x80x3 can be accomplished by reacting compound such as Cxe2x80x3 directly with a suitable alkyl borinic acid or ester under suitable palladium catalysis.
Additional electrophilic boron species that can be used have the structure: 
where R3 is as defined above and two R3 groups can form a ring.
Specific examples include: 
In Route 5 above, alcohol intermediate X1 can be activated for example by reaction with a sulfonyl halide such as methanesulfonyl chloride and a suitable base such as triethylamine and this electrophilic species reacted further with a nucleophile such as a substituted amine to afford the intermediate X2 which is then deprotected under the appropriate conditions. R2 is as defined above, and can be Rxe2x80x22. R3 is as defined above. 
In Route 6 shown above, the core indazole structure is formed in an annulation of a 2-halo-5-nitrophenyl aryl ketone Y1 with hydrazine to provide the requisite 3-aryl-5-nitroindazole Y2. Subsequent protection and reduction provides the amine Y4. As described for Route 2, diazotization, treatment of the diazonium salt with KI, followed by Pd catalyzed coupling of the iodo intermediate with an aryl boronic acid affords the protected 3,5-bisarylindazole intermediate Y6. Standard deprotection then yields the final products. R1 and R2 are as defined above, and can be Rxe2x80x21 and Rxe2x80x22.
The preparation of specific preferred compounds of the invention is described in detail in the following examples. The artisan will recognize that the chemical reactions described may be readily adapted to prepare a number of other kinase inhibitors of the invention. For example, the synthesis of non-exemplified compounds according to the invention may be successfully performed by modifications apparent to those skilled in the art, e.g., by appropriately protecting interfering groups, by changing to other suitable reagents known in the art, or by making routine modifications of reaction conditions. Alternatively, other reactions disclosed herein or known in the art will be recognized as having applicability for preparing other compounds of the invention.
In the examples described below, unless otherwise indicated all temperatures are set forth in degrees Celsius and all parts and percentages are by weight. Reagents were purchased from commercial suppliers such as Aldrich Chemical Company or Lancaster Synthesis Ltd. and were used without further purification unless otherwise indicated. Tetrahydrofuran (THF) distilled from calcium hydride and N, N-dimethylformamide (DMF) were purchased from Aldrich in Sure seal bottles and used as received. All solvents were purified using standard methods readily known to those skilled in the art, unless otherwise indicated.
The reactions set forth below were done generally under a positive pressure of argon or with a drying tube, at ambient temperature (unless otherwise stated), in anhydrous solvents, and the reaction flasks were fitted with rubber septa for the introduction of substrates and reagents via syringe. Glassware was oven dried and/or heat dried. Analytical thin layer chromatography (TLC) was performed on glass-backed silica gel 60 F 254 plates Analtech (0.25 mm) and eluted with the appropriate solvent ratios (v/v), and are denoted where appropriate. The reactions were assayed by TLC and terminated as judged by the consumption of starting material.
Visualization of the TLC plates was done with a p-anisaldehyde spray reagent or phosphomolybdic acid reagent (Aldrich Chemical 20 wt % in ethanol) and activated with heat. Work-ups were typically done by doubling the reaction volume with the reaction solvent or extraction solvent and then washing with the indicated aqueous solutions using 25% by volume of the extraction volume unless otherwise indicated. Product solutions were dried over anhydrous Na2SO4 or MgSO4 prior to filtration and evaporation of the solvents under reduced pressure on a rotary evaporator and noted as solvents removed in vacuo. Flash column chromatography (Still et al., J. Org. Chem., 43, 2923 (1978)) was done using Baker grade flash silica gel (47-61 xcexcm) and a silica gel: crude material ratio of about 20:1 to 50:1 unless otherwise stated. Hydrogenation was done at the pressure indicated in the examples or at ambient pressure.
1H-NMR spectra were recorded on a Bruker instrument operating at 300 MHz or 500 MHz and 13C-NMR spectra were recorded operating at 75 MHz. NMR spectra were obtained as CDCl3 solutions (reported in ppm), using chloroform as the reference standard (7.25 ppm and 77.00 ppm) or CD3OD (3.4 ppm and 4.8 ppm and 49.3 ppm), or internal tetramethylsilane (0.00 ppm) when appropriate. Other NMR solvents were used as needed. When peak multiplicities are reported, the following abbreviations are used: s (singlet), d (doublet), t (triplet), m (multiplet), br (broadened), dd (doublet of doublets), dt (doublet of triplets). Coupling constants, when given, are reported in Hertz (Hz).
Infrared (IR) spectra were recorded on a Perkin-Elmer FT-IR Spectrometer as neat oils, or as KBr pellets, and when given are reported in wave numbers (cmxe2x88x921). The mass spectra were obtained using LSIMS or electrospray. All melting points (mp) are uncorrected.
The starting materials used in the examples are commercially available and/or can be prepared by techniques known in the art.